01:119:115 Lecture Notes - Lecture 21: Macroevolution, Reproductive Isolation, Sexual Reproduction
17 Jan 2019
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Document Summary
Speciation = process where one species splits into two new species. Microevolution = changes over time in the alleles in a population. Macroevolution = a broad pattern where species are formed. The biological species concept = species is a group of population whose members have Potential to interbreed in nature and produce viable, fertile offspring. Species is defined by its niche (role in environment) Reproductive isolation = barriers that impede two species from producing viable, fertile offspring. Hybrids = offspring of crosses between different species. Reproductive isolation can be classified by whether factors act before or after fertilization and creation of a zygote. Two species encounter each other rarely, or not at all, because they occupy different habitats. Species that breed at different times of the day, different seasons, or different years cannot mix their gametes. Courtship rituals and other behaviors unique to a species and effective barriers.
